Table 1. Incidence of Induced Incompetence of the Internal Jugular Vein Valve and Cross-sectional Area of the Internal Jugular Vein in 46 Patients with Distal Internal Jugular Vein Cannulation and 45 Patients with Proximal Cannulation

Data are number of patients (%) or mean ± SD.

* Based on a semiquantitative five-grade scale, diagnosis of induced valvular incompetence was made if regurgitation grades during Valsalva maneuvers increased by > 1 grade at T2 and T3 compared with the baseline finding at T1.

† The incidence of valvular incompetence in the proximal cannulation group was significantly greater than in the distal cannulation group (P < 0.01).

‡ The incidence of valvular incompetence in the proximal cannulation group was significantly smaller after removal of the catheter than with catheter in place (P < 0.01).

§ Area^IJVsignificantly larger than at baseline (P < 0.01).

IJV = internal jugular vein; Preop = preoperative study; Postop = postoperative study.